When graphics are processed with an automatic drafting machine or a digital-font computerized phototypesetting machine, resultant graphics data are usually stored in a memory with reference to an orthogonal coordinate system. On the other hand, when a reproduced image is recorded, using a drum scanner or other type scanner, onto a sensitive film positioned on a recording drum, subscanning is performed continuously at a feed pitch equivalent to the width of the recording beam each revolution of the recording drum. This brings about distortion in the size of the subscanning pitch in the reproduced image on the film when the graphic data, stored in the memory in orthogonal coordinates, are fed to the scanner for image reproduction. In other words, the orthogonality of coordinates resulting from scanning with a recording beam width of .DELTA.x.sub.1 is distorted as shown in FIG. 1(b), wherein .DELTA.x.sub.1 is on the X-axis (subscanning direction) of the correct orthogonal coordinate system and wherein the Y axis, perpendicular to the X axis, represents the direction of rotation of the recording drum as shown in FIG. 1(a). When a recording beam having a width .DELTA.x.sub.2 larger than .DELTA.x.sub.1 is used, the reproduced image recorded on the same coordinate system exhibits greater distortion (.theta..sub.2 &gt;.theta..sub.1), as shown in FIG. 1(c). If the required accuracy of the reproduced image is not extreme, such distortion may be ignored and the conventional scanner can be used. However, when a recording head having several recording beams is used, or, to put it another way, when one scanning pitch (equal to the sum of the widths of the aforesaid several beams) is used, distortion of the reproduced image output may become a problem. Moreover, very high accuracy of recording dimensions is required in Raster-scanning automatic drawing machines. Wherever highly accurate image reproduction is required, the aforesaid distortion poses a major problem.